I've prototyped a spectrum analyzer LED project. I want to install it into my car, so that the spectrum analyzer runs off of my car stereo. But I can't figure out how to get the audio from the stereo. I use my phone to bluetooth to my stereo, so I can't use a 3.5mm splitter. I can't figure it out. Hopefully I posted this in the right section.
If you're lucky, the stereo will have outputs on the back of it that are intended to go to an amplifier.
Otherwise, a voltage divider off the speaker wires will get the audio signal but it will be dependent on the volume setting so you may need an AGC to front-end your analyzer.
Is there a way to convert that into 3.5mm audio? That's what my spectrum analyzer runs on.